1. Field of Invention
The invention relates to a lifting floor for swimming pools including means for elevation movement in which the lifting floor comprises a selfsupporting plate which is carried by lifting or raising elements in the form of lifting columns situated immediately adjacent the edge of the pool, particularly in the corners, which columns carry the driving means for the elevation movement and extend substantially the whole height of the swimming pool.
2. Description of Prior Art
A known device of this type (see Swiss Pat. No. 493,720) serves primarily to cover the swimming pool and thus is additionally supposed to reliably ensure that neither people nor objects fall in and is supposed further to enable the depth of the swimming pool to be adjusted in accordance with the requirements. For this purpose a single or multipart coverplate is arranged so as to be raised or lowered by means of lifting ropes which are powered by a winch device having a crank handle mounted on the pool periphery, or by means of threaded spindles and guide rods which are secured to or within the edge of the pool. In these known arrangements either the pool peripheral area is obstructed by the mechanical lifting devices or mountings for the guide rods or threaded spindles must be provided on resp. in the pool periphery thus incurring additional expense in construction. Particularly in the case of a subsequent conversion of an existing swimming pool, preferably a smaller private swimming pool, not only is relatively high expense necessary as a result of the required work on the walls, mountings etc. but also the volume of the pool which is available for use is restricted because either mechanical devices must be installed on the pool periphery or the spindles require a broader gap between the cover plate and the pool edge because they guide the plate by means of guide elements secured to its edge. Elastic strips are provided to cover this gap. However, these can only partially reduce the danger of an accident at the edge of the pool.